DESCRIPTION: (Applicant's Abstract) The proposed research is designed to study the substance use trajectories of two cohorts of Hispanic, African American, and non-hispanic white young adults. It builds on a previously completed study of the same cohorts on whom substance use and related data were obtained at three points in time, 1990, 1991, 1993. Two additional waves of data collection are planned. The overall objective is to secure data useful to the development of substance use/abuse prevention/intervention programs. As part of this goal, the research is designed to identify how substance use/abuse influences the personal and social transitions from early and mid-adolescence to young adulthood. The specific aims include: a) a longitudinal epidemiologic assessment of the prevalence and incidence of substance use; b) the identification of risk and protective factors associated with substance use behaviors; c) to identify the relationships between acculturation processes/conflicts and substance use; d) to determine the relationships between rejection/derogation and substance use and other forms of social deviance; e) to determine the relationships between exposure to social stressors and substance use; f) to determine the relationships between social/personal resources, including mastery and personal control and substance use behaviors; and g) to assess the reciprocal relationships between emotional distress and psychiatric problems and substance use and abuse.